Cap for a Receptacle

ABSTRACT

Closures for container openings, which comprise: a tap ( 16 ); and a piston ( 4 ) capable of axial movement along a longitudinal axis ( 12 ) within the tap; wherein the tap has a product conduit ( 5 ) and a venting conduit ( 6 ) blockable by the axially movable piston are disclosed.

The invention relates to a closure for an opening of a container, having a tap having a product conduit blockable by way of an axially movable piston.

A closure of this kind is described in International Patent Application PCT/US2003/026713. To allow product to be delivered via the product conduit, the container is vented via a separate venting opening, e.g. on the upper side of the container. Such venting is necessary in order to guarantee continuous product flow. A disadvantage of this embodiment is the separate placement of the venting opening. In this case two separate openings must be provided in the container, i.e. one for product delivery and one for venting. This greatly limits the stylistic possibilities for the container in terms of attractiveness to the customer and manufacturing engineering.

It is the object of the present invention to simplify and improve the removal of product from a container.

This object is achieved by the features of the characterizing part of claim 1.

The closure according to the present invention for an opening in a container is equipped with a tap that comprises a product conduit. This product conduit is blockable by an axially movable piston. A closure according to the present invention additionally comprises a venting conduit for the container. Because the product conduit and venting conduit are contained in one and the same closure, a separate venting system is no longer necessary.

For precise movement of the piston, preferably a guide is provided for the piston in which the latter is guided in axially movable fashion. Because this guide can, for example, be embodied substantially as an orifice, it can also assume a conduit function, as will be set forth in further detail below.

In a closure according to the present invention, the tap and a closure cap can preferably each be configured in terms of their own function. A closure cap of this kind can be connected to the container by way of a variety of closure mechanisms, e.g. a screw closure or snap/detent closure.

The tap and the piston movable therein are particularly easily to access and handle if the longitudinal axis of the piston and of the piston guide is at a specific angle to the center axis of the closure cap, preferably perpendicular thereto.

A particularly compact and economical configuration provides for both the product conduit and the venting conduit to open into the piston guide of the tap. The terminating openings of the two conduits are preferably spaced apart from one another inside that guide.

To ensure that both the product conduit and the venting conduit are blocked off in sealed fashion by the piston, it can be advantageous to equip the piston with at least one piston ring as a sealing element. In the closed position of the piston, for example, these sealing elements of the piston can seal off the respective terminating opening, between the piston and piston guide, above and below that opening. Possible embodiments for such sealing elements are, for example, piston rings or O-rings. The present invention is not, however, limited to these two embodiments; all possibilities for sealing such designs are additionally conceivable in the context of this invention.

It can furthermore be advantageous in terms of the invention for the piston to be made hollow, and to be equipped with at least one lateral orifice. Such an orifice could, for example in the open position of the piston, correspond with the mouth of the venting conduit in such a way that said mouth is uncovered. Venting of the container is thus ensured via the tap, the hollow piston, the orifice of the piston, and the venting conduit.

For improved product delivery, it can be advantageous if the piston, in that open position, completely uncovers the product conduit. Complete uncovering of this kind ensures a rapid and uninterrupted stream of product.

Depending on the manner in which a closure according to the present invention is used, it can be advantageous if the piston in the piston guide is subject to a return force. A return force of this kind could be applied, for example, by way of a tensioning element, e.g. a spring, preferably a helical spring. The advantage of such a return force in the context of a suitable design can be that as a result thereof, in a closure according to the present invention, the piston is held in the closed position. The force with which the piston is held in that closed position can be adjusted by means of the nature of that return force, or by the selection of the tensioning element. In the case of a spring as tensioning element, it can be advantageous to set that force in the range from 3 N to 8 N, preferably in the range from 4 N to 5 N. The same tensioning element can serve, for example, in the context of a closure according to the present invention, to apply a force that is necessary for holding the piston in the open position. That force can be, for example, in the range from 10 N to 25 N, preferably in the range between 12 N and 18 N.

In order to make it easier, in the context of a closure according to the present invention, for the user to move the piston, the latter can be connected, for example, to a handling element. This handling element can be both embodied integrally with the piston and connected thereto via insertion, snap/detent, or similar connections. The embodiment of the handling element is to be provided depending on the desired manner of operation of the tap. For example, it is possible in the context of the invention to equip the handling element with two contact surfaces for the user's fingers. These contact surfaces could preferably be adapted for utilization by the user's index and middle fingers. The contact surfaces could, for example, protrude in ear-shaped fashion.

It can furthermore be advantageous to equip the tap of a closure according to the present invention with a stop that limits the movement of the piston out of the closed position toward the open position. This has the advantage that unintentional disassembly of the tap upon opening is prevented by such a stop. Depending on the manner of operation provided for the tap, it can be advantageous to equip this stop with a resting place for the user's thumb. For the embodiment of the handling element having two contact surfaces for the user's fingers, this resting place of the stop thus constitutes the counter-brace for the piston opening movement. For this possible manner of operation of the tap of a closure according to the present invention, the movement of the piston into the open position occurs in accordance with the syringe principle, i.e. the user makes contact against the handling element with the index and middle fingers, places his or her thumb on the resting place of the stop, and pulls the handling element toward the thumb. The stop position and stop travel are preferably selected so that upon arrival at the stop, an orifice in the piston corresponds with the mouth of the venting conduit.

In experiments with a closure according to the present invention, it has been found that it can be advantageous to adapt the ratio of the diameters of the product conduit and venting conduit to the maximum fill height of the container and to the viscosity of the product. In the context of the invention such a diameter ratio can be, for example, in the range between 5:1 and 15:1, and can preferably be, for example, 10:1. Adapting the diameters to the fill height and viscosity can guarantee that venting occurs only through the venting conduit, and that product is delivered only through the product conduit. Unintentional closure of the venting conduit due to the inflow of product can be prevented, for example, by adapting this ratio.

A closure in the context of the invention can be used, for example, for containers having a maximum fill height in the range between a liquid column of 150 mm and 250 mm. The viscosity of the product can be selected, for example, in the range between 100 and 1800 mPa, preferably in the range between 800 and 1200 mPa.

It has been found in further experiments that in closures, the problem can occur that residual quantities of product in the region of the end of the piston can cause extended “drooling.” Such drooling can be prevented, or at least controlled and directed, for example by the provision of a centeredly mounted point at the end of the piston. Potential residual quantities of product can rapidly flow off from such a point. Drooling is thus limited to a very short time span after closure of the valve, and to a specific center region.

A further design step in order to prevent this drooling can be, for example, to reduce the diameter of the piston guide and of the piston of a closure according to the present invention at the lower end. This reduction in diameter can be accomplished both continuously and in steps. The result of this diameter reduction is to minimize the volume in the region of the delivery opening. The residual quantity of product upon closure of the tap is thereby minimized. A smaller residual quantity also means a shorter drooling time.

It has been found in further experiments that an additional sealing of the delivery opening can also be advantageous in preventing drooling. The piston of a closure according to the present invention can, for example, be sealed, by way of a conical termination at the lower end, against the delivery opening adapted to that termination, in the manner of a valve seat.

To ensure that in a closure in the context of the invention, upon venting through the venting conduit, air bubbles can easily detach from the container in the interior thereof, it can be advantageous to extend that venting conduit into the container. This extension need not obligatorily end above the maximum liquid level of the container. In other words, this extension can form a snorkel, but does not need to. This extension is preferably smaller in its expression than the closure cap.

The teaching of the invention is further explained in more detail below in conjunction with the explanation of preferred exemplifying embodiments with reference to the drawings.

In the drawings:

FIG. 1 is an oblique view of a preferred exemplifying embodiment of a closure according to the present invention;

FIG. 2 is a section through a preferred exemplifying embodiment of a closure according to the present invention in the closed position;

FIG. 3 is a section through a preferred exemplifying embodiment of a closure according to the present invention in the open position.

FIGS. 1 to 3 of the drawings show a preferred embodiment of a closure according to the present invention for an opening of a container. In FIGS. 2 and 3, closure cap 10 is shown at the right and tap 16 at the left in each case.

Product conduit 5 and venting conduit 6 connect the interior of the container to piston guide 8. FIG. 2 shows how piston 4, in the closed position, closes off the terminating openings of the two conduits. In the present exemplifying embodiment of a closure according to the present invention, sealing elements 14 are mounted on the piston. O-rings are used here as sealing elements. These sealing elements are located above and below the respective terminating openings of the conduits. They thus seal off both venting conduit 6 and product conduit 5 in annular fashion, toward the top and bottom, between piston 4 and piston guide 8.

Piston guide 8 is equipped at the upper end with a stop 9 that is connected to said guide by means of a snap/detent connection. A helical spring 3 is provided as a tensioning element between stop 9 and piston 4. This spring 3 exerts a return force on the piston and holds it in the closed position with a defined force.

In the present exemplifying embodiment, center axis 12 of piston guide 8 and of piston 4 extends perpendicular to center axis 11 of closure cap 10. This promotes easier operability by the user. Connected to the piston is a handling element 7 that is visible in FIGS. 1 to 3. In the present exemplifying embodiment of the invention, this element is connected integrally to piston 4. This handling element 7 forms two contact surfaces 17 on the underside, against which the user's fingers can come to rest. For the preferred use in the context of the present embodiment, these contact surfaces are adapted to the user's index and middle fingers. A resting place 18, preferably for the user's thumb, is provided on stop 9 as a counter-brace for the piston's opening movement. In order to bring piston 4 out of the closed position as shown in FIG. 2 into the open position as shown in FIG. 3, the user makes contact with his or her index and middle finger against the underside of handling element 7 at its contact surfaces 17, and places his or her thumb on resting place 18 of stop 9. Bringing the index and middle fingers toward the thumb in a movement similar to that of a syringe causes piston 4 to be moved axially in piston guide 8, against the return force of tensioning element 3, into the opening position. A continuous application of force by the user is necessary in order to hold the piston in the open position. An inadvertent delivery of product is thus precluded with the present embodiment of the invention, since once it is released by the user, piston 4 is immediately guided by tensioning element 3 back into its rest position, and thus closes off both venting conduit 6 and product delivery conduit 5.

In the present exemplifying embodiment, piston 4 possesses an orifice 2 that is arranged below the lower sealing element 14 for the venting conduit and above the upper sealing element for product conduit 5. When piston 4 is then brought into the open position in the manner described, opening 2 ends up at the level of the venting conduit. At the same time, at the lower end piston 4 completely uncovers product conduit 5.

Product can then be delivered out of the container, through the product conduit and the uncovered lower part of piston guide 8, through delivery opening 15. The container is vented through venting conduit 6. In the present exemplifying embodiment, air travels through lateral slots or cutouts on piston guide 8, through the interior of the hollow piston 4 and orifice 2, into the venting conduit and thus into the container. In the present exemplifying embodiment, venting conduit 6 is extended into the container to enable easier detachment of air bubbles during the venting operation. When the piston is then, after completion of the delivery operation, moved back into its closed position by the return force of the tensioning element, the venting conduit and product conduit are simultaneously closed. The product flow through product conduit 5 is, so to speak, sheared off. This shearing-off already minimizes the residual quantity of product that remains in tap 16 after the latter is closed. To allow such residual quantities to flow off quickly, in the present exemplifying embodiment a point 13 is provided at the lower end of piston 4, at which point any residual quantities of product can collect and quickly drip off. The problem of drooling is thus reduced to a very short period after closing. Below the product conduit, both piston 4 and piston guide 8 are reduced in diameter. Piston 4 is equipped at the lower end with a conical termination that additionally seals delivery opening 15 in the closed position.

To allow the present closure to be attached to a container, e.g. for liquid washing agent, closure cap 10 is equipped with an internal thread. Any other form of connection is, however, also conceivable.

The present embodiment of a closure according to the present invention can thus be used, for example, on a container for liquid washing agent and can close it off. For product delivery, the user can open the tap with one hand (using three fingers) and thus has the other hand free to hold, for example, a measuring vessel. Active closing is not necessary, since piston 4 automatically assumes the closed position as a result of the return force of tensioning element 3. The user also does not need to wait very long for any residual quantities to drip off once the tap has closed, since drooling time is minimized by the design features described above. 

1-35. (canceled)
 36. A closure (1) for a container opening, the closure comprising: a tap (16); and a piston (4) capable of axial movement along a longitudinal axis (12) within the tap; wherein the tap has a product conduit (5) and a venting conduit (6) blockable by the axially movable piston.
 37. The closure according to claim 36, wherein the tap comprises a guide (8) for the axially movable piston.
 38. The closure according to claim 36, wherein the closure comprises a closure cap (10) having a center axis (11), and wherein the longitudinal axis of the piston is perpendicular to the center axis of the cap.
 39. The closure according to claim 36, wherein the product conduit and the venting conduit are each connected to the guide of the tap by a terminal opening.
 40. The closure according to claim 39, wherein the terminal openings of the product conduit and the venting conduit are spaced apart from one another in the guide.
 41. The closure according to claim 36, wherein the piston comprises at least one piston ring as a sealing element.
 42. The closure according to claim 39, wherein the piston comprises sealing elements (14) disposed on the piston such that in a closed position the sealing elements are disposed above and below the terminal openings of the product conduit and the venting conduit providing a seal between the piston and the guide.
 43. The closure according to claim 42, wherein the sealing elements comprise piston rings.
 44. The closure according to claim 42, wherein the sealing elements comprise O-rings.
 45. The closure according to claim 36, wherein piston is hollow and has at least one lateral orifice (2).
 46. The closure according to claim 45, wherein the at least one lateral orifice is disposed along the piston such that in an open position the at least one lateral orifice corresponds with the venting conduit to provide fluid communication between the conduit and the hollow piston.
 47. The closure according to claim 36, wherein the product conduit is completely uncovered by the piston in an open position.
 48. The closure according to claim 46, wherein the product conduit is completely uncovered by the piston in an open position.
 49. The closure according to claim 36, wherein the piston is biased in a closed position.
 50. The closure according to claim 36, further comprising a tensioning element (3) disposed therein against the piston such that the piston is biased in a closed position within the tap.
 51. The closure according to claim 50, wherein the tensioning element comprises a helical spring.
 52. The closure according to claim 36, further comprising a handling element (7) connected to the piston and disposed on the exterior of the tap for moving the piston.
 53. The closure according to claim 52, wherein the handling element comprises two contact points (17) for application of finger pressure by a user.
 54. The closure according to claim 53, further comprising a tensioning element (3) disposed therein against the piston such that the piston is biased in a closed position within the tap.
 55. The closure according to claim 54, wherein the piston biased in a closed position with a force of 3 to 8 N.
 56. The closure according to claim 54, wherein a force of 10 to 25 N is required to hold the piston in an open position against the tensioning element.
 57. The closure according to claim 36, wherein the tap comprises a stop (9) such that movement of the piston out of a closed position to an open position is limited.
 58. The closure according to claim 53, wherein the tap comprises a stop (9) such that movement of the piston out of a closed position to an open position is limited, wherein the stop comprises a resting place (18) for application of thumb pressure by the user such that the resting place serves as a counter-brace for piston movement.
 59. The closure according to claim 36, wherein the ratio of the diameter of the product conduit and the diameter of the venting conduit is 5:1 to 15:1.
 60. A container having an opening enclosed by the closure according to claim 36, wherein the container has a maximum fill height of product contained therein of 150 nm to 250 nm.
 61. The container according to claim 60, wherein product contained within the container has a viscosity of 100 to 1800 mPas.
 62. The container according to claim 60, wherein the ratio of the diameter of the product conduit and the diameter of the venting conduit is adapted to the maximum fill height and the viscosity of product contained therein.
 63. The closure according to claim 36, wherein the piston has a lower end comprising a central point (13).
 64. The closure according to claim 37, wherein the piston and the guide each have a lower end having a reduced diameter.
 65. The closure according to claim 36, wherein the tap comprises a delivery opening having a conical termination.
 66. A container having an opening enclosed by the closure according to claim 36, wherein the venting conduit extends into the container. 